It is known to attach firing tips, such as those made from various precious metals,to spark plug electrodes for the purpose of improving the resistance of the electrode to corrosion or oxidation, as well as spark erosion that may occur when the spark plug is in use in a combustion chamber of an internal combustion engine. Different methods and techniques have been developed for carrying out this attachment, including certain laser and resistance welding techniques.
Because of the extremely harsh environment in a combustion chamber, however, there is always a need to try and improve the strength of the attachment between the firing tip and the underlying electrode and, where possible, to improve the thermal conductivity across that junction.